1. Field of the Invention
The invention lies in the field of conveying and processing printed products and concerns a method and an installation according to the generic terms of the corresponding independent claims. The method and installation serve the insertion of flat articles into continuously conveyed printed products. The printed products are e.g. newspapers, periodicals or brochures, i.e. folded or bound printed products, which are opened for the purpose of insertion. The flat articles can be further printed products (e.g. folded or bound supplements, postcards, leaflets) or other articles (e.g. CDs, sample sachets) and, into each printed product, one article is inserted or a group of articles, which group is manageable as a single unit (plurality of similar or different flat articles).
2. Description of Related Art
According to the state-of-the-art technology, printed products are opened and flat articles inserted therein by supplying then e.g. to a rotating insertion drum, where they are held open in V-shaped compartments and are shifted in axial direction simultaneously with the rotation. Thus, they are conveyed past one supply point with each rotation of the drum. At each supply point a flat article is inserted, usually from above, into each passing printed product so that by the effect of gravity the article is driven towards and positioned adjacent to the inner side of the fold or spine edge of the printed product. The insertion drum is a large and highly sophisticated installation, whose use is really only justified when several supply points are necessary, i.e. when a plurality of different flat articles is to be inserted into each printed product and the plurality of these articles can not or ought not to be handled as one unit.
For inserting into each opened printed product just one flat article or a group of articles handled and inserted as one unit, simpler installations are more suitable, e.g. the installation described in the publication EP-0448679 (or U.S. Pat. No. 5,165,672, Wamac). This installation comprises rotating V-shaped compartments, in which the printed products are opened and conveyed past a supply point, where the flat articles are inserted. As the printed products in the V-shaped pockets do not have to be shifted transverse to the main conveying direction as they would be in the insertion drum, they do not need to be transferred to a means of conveyance equipped for this transverse motion, but, for the insertion, can remain in the grasp of the same grippers by which they are conveyed into, and retrieved from the rotary system comprising the compartments. To this purpose each compartment comprises two section and the grippers of the gripper conveyor are conveyed between these sections and aligned with their base along a part of the compartment rotation. As the printed products held in the compartment by the grippers approach the supply point, they are opened and held open while being conveyed past the supply point. The grippers are also temporarily opened during this conveyance past the supply point. In order to keep the printed products open in the V-shaped compartments and to maintain the position of their fold or spine edge in the gripper while the latter is open, the compartments are furnished with clamping means and are conveyed past the supply point in an essentially straight and horizontal line (with the opening facing upwards).
The installation according to EP-0448679 is simpler than an insertion drum, yet is still rather elaborated. Furthermore, it comprises the disadvantage that the grippers, which convey the printed products into the compartments, within the compartments past the supply point and then out of the compartments, must be spaced from each other such that the insertion procedure is possible during a straight lined, horizontal conveyance. This however is not the case for gripper of gripper conveyors as widely used for the conveyance of printed products, which grippers are usually spaced from each other by approximately 10 cm. An opening of no more than 10 cm is exceedingly narrow for the insertion of individual flat articles, particularly at high conveying speeds, and it is too small for the insertion of a group of articles. For an insertion using the installation disclosed in EP-0448679, the printed products must therefore be transferred to a special gripper conveyor with larger gripper spacing, which means further complexity of the installation and higher conveying velocity for the same capacity.
The object of the invention is to improve the method and installation according to the state-of-the-art technology for the insertion of flat articles is continuously conveyed printed products, i.e. the state-of-the-art technology as e.g. known from the publication EP-0448679, to the extent that they become simpler, and that they in particular can be used in conjunction with a commonly used gripper conveyor, i.e. with a gripper conveyor with a gripper spacing which is not large enough for the insertion according to EP-0448679.
This object is achieved by the method and the installation as defined in the claims.